The Institute of Electrical and Electronics Engineers (IEEE) will begin sifting through a record number of proposals for a high-speed amendment to the 802.11 standard next week, but wireless chip makers are already jumping the gun with pre-standard products.
802.11n is intended to more than triple the real throughput of wireless LAN (WLAN) by focussing on enhancements to the MAC (media access control) interface, rather than the physical layer. This should mean the real throughput more closely matches the theoretical maximum rate. Currently the fastest WLAN gear has a real-world limit of 30Mbit/s, which the "n" standard will push up to at least 100Mbit/s.
As with 802.11b and 802.11g, initial demand is being driven by an insatiable US consumer market for applications such as wireless video transfer in the home, but the higher bandwidth is expected to benefit enterprise applications such as voice over IP (VoIP). "Quality of service is absolutely more important than sheer bandwidth (for VoIP), but more bandwidth never hurts," said Dean Bubley, founder of Disruptive Analysis. "For one thing it makes QoS work better if there's lots of headroom."
With the proliferation of wireless devices in the office, 802.11n could also combat network congestion. "With wireless, the bandwidth is contended between multiple devices on the same access point. You don't necessarily need 200Mbit/s to each individual device, it is shared amongst users in the enterprise or on a hotspot."
Starting on Sunday, the 802.11n task group will begin to pick and choose among the 61 proposals submitted since the mid-January call for entries. The process is likely to be tortuous, with big players such as Atheros, Broadcom, Intel, Sony and Texas Instruments reportedly lined up in opposing camps, and a finished standard isn't expected until 2005 or 2006.
The standards body won't have time to sit on its hands, however, with vendors including Broadcom and Airgo jumping to release proprietary products that use the technology they've submitted to the 802.11n group. Airgo said recently it had signed up four customers to its True MIMO smart-antenna technology, with two, SOHOware and Planex, currently shipping True MIMO-based products that are backward-compatible with existing 802.11 standards.
Airgo is not shy about calling True MIMO "pre-n", or pre-standard 802.11n, claiming the popularity of its technology in the marketplace will ensure it becomes a cornerstone of the as-yet-non-existent standard. Some industry observers agree. "Progress commercializing MIMO technology is leading the industry to adopt the technology for 802.11n," said Gartner semiconductor analyst Joseph Byrne.
Airgo leads a faction called the World Wide Spectrum Efficiency (WWiSE) group, which favours sticking with the 20MHz bandwidth and using advanced coding techniques and MIMO antennas, according to a report in the industry newspaper EE Times. Broadcom, Conexant, Mitsubishi, Motorola, STMicroelectronics and Texas Instruments also back the WWiSE.
A rival camp called TG nSynch is led by Atheros, with Intel, Matsushita, Philips and Sony as members. This group favours the 40MHz bandwidth, allowing higher throughput to be achieved with simpler coding techniques, according to the report. Unlike the similar Ultrawideband standards process, where participants have come to a consensus on technology, with 802.11n the rivals are more or less equally powerful, according to industry observers.
This appears to be partly what's behind Airgo's aggressive commercialisation of MIMO, according to analysts. "The idea is to pitch it to the standards body while commercialising it anyway," said Bubley. "Otherwise it might never get to market, unless it's picked up as part of the standard. It's a high-risk strategy but you can't blame them."
Broadcom, which successfully marketed pre-standard 802.11g chips, told reporters in January that it was planning to sample 802.11n chips this year, but the company later said it would wait for the IEEE.
Pre-standard equipment carries the risk of inter-operability problems, but consumers aren't as sensitive to this issue as businesses, according to analysts. What's more, commercial demand can spur standardisation. "Without market demand to speed it up, standards processes can go on for a long time," said analyst Robin Duke-Woolley of E-Principles. "There is a need for proprietary products to drive the market."
The stakes are high for 802.11n, partly because other 802.11 "Wi-Fi" technologies are already so popular - it is easier for users to upgrade to a new Wi-Fi flavour than to switch to a new technology such as Ultrawideband, say analysts. Partly because of this, 802.11n is likely to push Ultrawideband out of consumer electronics for all but a few niche uses, according to a report by ABI Research last week.
The 802.11i specification for improving WLAN security was approved last week, and a host of other WLAN standards are also on the way. Among them are "e", for quality of service, "r", for improvements to roaming between networks, and "f", for defining how access points interact.